An electric vehicle uses one or more electric motors for propulsion of the vehicle. The electric motors are powered by rechargeable batteries on-board the vehicle. A driver of an electric vehicle typically recharges the batteries of his vehicle at home by connecting the vehicle to a charging station that transfers electric energy to the vehicle. A utility company supplies the electric energy to the charging station and charges the driver for the electric energy.
Utility companies charge different rates for electric energy consumed based on the time, day, month, and/or calendar season when it is consumed. Typically, a utility company charges its lowest rates in the early morning and late at night. Those time periods are often referred to as off-peak hours because that is when overall energy consumption is low. An electric vehicle may be set to only charge during off-peak hours in order to save the owner money. However, such a setting may be a major inconvenience and potentially dangerous because it can cause a driver to be stranded. Assume, for example, that a driver of an electric vehicle arrives home at 6 PM with little or no charge left in the batteries of the vehicle, that the vehicle is set to charge during off-peak hours (e.g., after 10 PM), and it is the only vehicle that the driver's family owns. If there is an emergency at 8 PM and the driver has to rush, for example, to a hospital, the driver will be stranded because the vehicle was not charging between 6 and 8 PM.
Thus, there is a need for a way to be able to charge an electric vehicle in a way that takes advantage of economic electric energy rates offered by utility companies but at the same time prevents a driver from becoming stranded.